1. Technical Field
The present disclosure relates generally to surgical portals for use in minimally invasive surgical procedures, such as endoscopic and/or laparoscopic procedures, and more particularly, relates to a surgical portal that allows multiple surgical instruments to be inserted through a single incision.
2. Description of Related Art
Today, many surgical procedures are performed through small incisions in the skin, as compared to the larger incisions typically required in traditional procedures, in an effort to reduce both trauma to the patient and recovery time. Generally, such procedures are referred to as “endoscopic”, unless performed on the patient's abdomen, in which case the procedure is referred to as “laparoscopic”. Throughout the present disclosure, the term “minimally invasive” should be understood to encompass both endoscopic and laparoscopic procedures.
During a typical minimally invasive procedure, surgical objects, such as surgical access devices (e.g., trocar and cannula assemblies) or endoscopes, are inserted into the patient's body through the incision in tissue. In general, prior to the introduction of the surgical object into the patient's body, insufflation gas is used to enlarge the area surrounding the target surgical site to create a larger, more accessible work area. Accordingly, the maintenance of a substantially fluid-tight seal is desirable so as to inhibit the escape of the insufflation gas and the deflation or collapse of the enlarged surgical site.
To this end, various access devices with sealing features are used during the course of minimally invasive procedures to provide an access for surgical objects to enter the patient's body. Generally, an access device is made of resilient material and has one or more ports, and each port is designed to accommodate one surgical object to be inserted therethrough. In the prior art, when a surgical object advances through a port, the resilient material is adapted to frictionally engage the surgical object, thus forming a seal between the surgical object and the port along the length of the port.
Further, in the prior art, each port is open-ended. Therefore, before the insertion of surgical objects through the open-ended ports, the insufflation gas may escape from the patient's body cavity through the open-ended ports. For the same reason, foreign matter may inadvertently enter into the patient's body cavity through the open-ended ports. To overcome this problem, cannula assemblies have been used heretofore to couple with the prior access devices together providing a sealed passage for the surgical objects to access the patient's body. A cannula is a tubular member that is positioned within the prior access device through the port, providing a passage for a surgical object to access the patient's body. Typically, the cannula includes respective proximal and distal ends, an elongate member disposed therebetween, and a seal housing positioned at the proximal end. The elongate member defines an opening dimensioned to permit the passage of surgical object. Further, the elongate member is longer in length than that of the open-ended port. Thus, upon positioning, the distal end of the elongate member of the cannula reaches beyond the distal end of the open-ended port and extends into the patient's body cavity. Furthermore, the seal housing of the cannula is adapted to receive the surgical object inserted through the elongate member so as to form a substantially fluid-tight seal with the surgical object. Because the diameter of the seal housing is substantially larger than the diameter of the open-ended port, the seal housing is thus inhibited from entering the open-ended port. Therefore, upon positioning, the seal housing is positioned outside the access device, e.g. positioned above the opening of the open-ended port. Further, the cannula includes a closure valve which is normally closed in the absence of a surgical instrument. The closure valve thus inhibits gas leakage and introduction of foreign matter in its closed state, therefore serving as a complement to the open-ended ports.
In the prior art, during the operation of the access device, a surgeon introduces the access device into the incision either before or after introducing insufflation gas into the surgical site. After placing the prior access device into the incision, the surgeon inserts a cannula into each open-ended port of the access device, and then inserts a surgical instrument into each cannula. In multiple port access devices, cannulas are often staggered relative to the access device to facilitate movement of the surgical instruments. When multiple cannulas are positioned within the access device concurrently, the seal housings of the cannulas are all positioned above the access device. The seal housings may clash against each other as the surgeon manipulates multiple surgical instruments that are inserted through the multiple cannulas simultaneously. The collisions among the seal housings not only cause great interference with the movements of the surgical instruments, but also limit the number of cannulas that can coexist within an access device of a given size, thereby reducing the number of surgical instruments that can simultaneously operate through the access device. Similarly, the distal ends of the cannulas, which are positioned inside the patient's body cavity, may also cause interference with the instrument motion, as the distal ends of the cannulas clash within the body cavity. Further, in the prior art, the surgical instruments that are inserted through a single access port via cannulas have a limited freedom of movement constrained by the physical characteristics of the cannulas and the open-ended ports. For instance, an open-ended port provides an open channel in a longitudinal direction of the access port. For that reason, the elongate member of the cannula, when positioned within the open-ended port, provides a channel for the surgical instruments to maneuver in a longitudinal direction relative to the access port. However, to reach a desired operation site within the patient's body cavity, the surgeon often needs to move the surgical instrument in a slanting or sloping direction relative to the access port.
Thus, to facilitate and provide greater freedom of movement of the surgical instruments and to avoid potential interferences therewith, a continuing need exists for an access device with enhanced sealing features and enhanced port features.